pkg_resources.DistributionNotFound: The 'leap.bitmask==0.10rc2+1.g41ec6a42.dirty' distribution was not found and is required by the application

I installed the Buster bitmask-qt package and tried to run bitmask, and got this:

micah@muck:~$ bitmask
Traceback (most recent call last):
  File "/usr/bin/bitmask", line 6, in <module>
    from pkg_resources import load_entry_point
  File "/home/micah/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3037, in <module>
    @_call_aside
  File "/home/micah/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3021, in _call_aside
    f(*args, **kwargs)
  File "/home/micah/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3050, in _initialize_master_working_set
    working_set = WorkingSet._build_master()
  File "/home/micah/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 655, in _build_master
    ws.require(__requires__)
  File "/home/micah/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 969, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/home/micah/.local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 855, in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'leap.bitmask==0.10rc2+1.g41ec6a42.dirty' distribution was not found and is required by the application
micah@muck:~1$